Giáo trình Khí nén - Thủy lực (Nghề: Cắt gọt kim loại - Trung cấp) - Trường TCN Kỹ thuật công nghệ Hùng Vương

UY BAN NHAN DAN QU4N 5
TRUONGTRUNGCAPNGHEKYTHU4TCONGNGHtHUNGVUONG

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GIAOTRINH

Khi nen - Thu)' l\fC
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Nghe: Cat gQt kim lo~i
TRINH DO• TRUNG CAP

TPHCM-2019



1

LOIMOBAU
V&i S\f phat tri~n cong ngh~ hi~n nay, di_ic bi~t la trong linh V\fC t\f
dqng boa thi di~n khi nen, khi nen, thiiy l\fc va nhfrng rrng dl}.ng dong
m<}t vai tro rit quan trQng va chu ch3t trong h~ th3ng t\f dqng boa.
V&i ml}.c dich dao t~o dqi ngfi thuit vien chit hrgng cao va chu~n
boa dtrQ'C tai li~u cho mQi ngtrO'i mu3n tim hi~u, nghien CU'U v~ PLC.
Nhfrng mong mu3n lam th~ nao d~ mQi ngtrO'i co th~ cung nghien CU'U va
dtra rrng dl}.ng khi nen vao san xuit. V&i nhfrng ki~n thfrc va hi~u bi~t v~

linh V\fC khi nen, nhfrng tai Ii~u tham khao tir nhi~u hang, tai li~u v~ h~
th8ng MPS cua hang Festo da giup toi hoan thi~n tai Ii~u di~u khi~n khi
nen I.
Trong qua trinh lam vi~c va nghien crru t~i TrtrO'ng TCN - KTCN
Hung VtrO'ng dtrgc S\f giup dcr tin tinh tir nha trtrO'ng, di_ic bi~t la ThAy
Ph~m Phu ThQ d~ toi hoan thanh tai li~u nay. Xin chan thanh cam O'n
ThAy luon dqng vien va giup dcr v~ tinh thin 1,n ki~n thrrc chuyen mon
d~ em hoan thanh t6t cu8n sach nay.
Nhfrng ki~n thrrc cua toi cfing chi nho be va mong cung trao dBi,
hqc hoi va cung chia se v&i mQi ngtrO'i trong cung linh V\fC. N~u co sai
sot va bB sung mong S\f giup dcr cua tit ca nhfrng b~n be trong cung linh
V\fC giup.
Qugn 5, ngay

thang

Tham gia bien soq,n
1. Trdn Van Hilu
2.H6 Vi:nhAn

nam20 ...


2
MlJC LlJC
LOI MO DAU .......................................................................................................... 1
CHUONG I: KHA1 NIEM VE KHi NEN VA UNG DUNG CUA KHi NEN .. 4
1. sv PHA.T TRI@N CuA Ky THU~T KHi NEN ........ ~ ...................................... 4
IL NHuNG D~C TRUNG CuA KHONG KHi NEN .......................................... 4
111.D!C TiNH CUA KHi NEN ........................................................................... 6

IV. cAc Di;\.1 LUONG V!TLY .................................................................... 6
V. KHA NANG UNG Dl)NG CUA KHi NEN ................................................ 10
1. Trang li'nh vvc di Su khi@n ............................................................................. 10
2. H~ th6ng truySn d(:mg .................................................................................... 10
VI. VU NHUdC DIEM CUA HE THONG TRUYEN DONG BANG KHi
NEN .............. :............................. :...................................... :........................... 10 ·
1. Vu di@m ................................................................................................ 10
2. Nhuoc di@m .......................................................................................... 11
VIL cAc LON MAY KHi NEN VA THIET BJ XU LY KHi NEN ........... 11
1. May nen khi: ......................................................................................... 11
2. Thi@t bi xu ly khi nen ............................................................................ 12
3. Cac ph~n tu ch§.p hanh (working elements) ........................................... 14
C~UONG II: THIET KE, LAP DJT VA V4N HANH HƠ THONG KHi
NEN ....................................ã.......................................ã....ã......................................ã 17
1. cAc LON VAN KHi NEN ......................................................................... 11
1. Ky hi~u chung cua van diSu khi@n dao chiSu (Directional control
valve) ......................................................................................................... 17
2. Cac van dao chiSu di Su khi@n b&ng khi nen ........................................... 19
11. cAc LON v AN LOGIC ............................................................................. 23
1. Van logic AND ( Dual Pressure Valve - AND Function) ( Hinh 2.29) .. 23
2. Van logic OR (Shuttle Valve - OR function) (Hinh 2.30) ................... 24
3. Van m<)t chiSu (Non-Return Valve) ..................................................... 24
4. Van xa nhanh ........................................................................................ 24
111.VAN DIEU CHINH LUU LUONG ............................................................. 25
IV. VALVE DIEU CHiNH THOI GIAN ...................................................... 26
V. VAN TUAN TV AP SUAT (Pressure sequence valve) ............................... 28
v1. ca cAu cHAP HANH .......................................................................... 28
CHUONG III: THIET KE VA DIEU KHIEN KHi NEN UNG DlJNG ......... 32
I. PHVdNG PHAP MO TA BAI TOAN DIEU KHIEN ................................ 32
1. Bi@u d6 hanh trinh bu&c (Displacement-Step Diagram) ..................... 32

2. Phuong phap dung so d6 chuc nang ...................................................... 36
11. cAc cAu TRUC DIEU KHIEN HJ$ THONG KHi NEN .......................... 36
1. DiSu khi@n trgc ti@p: .............................................................................. 36
I:'\";., kh•A
. ' t•A
1en g1an
1ep: ............................................................................ . 37
2 . uleU
3. Di Su khi@n tv d<)ng theo hanh trinh ....................................................... 37
4. Di Su khi@n tv d<)ng theo thai gian ......................................................... 39
111.BIEU DO TRL;\NG THAI ............................................................................. 41
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3
1. Di@u khiSn tv d9ng theo ap suit ............................................................ 41
2. f)i@u khiSn theo t~ng ............................................................................. 41
CHUONG
IV: LAP l>~T, V4N HANH VA KIEM TRA Hlj: THONG l>Ilj:N
,
,
-KHI NEN .............................................................................................................. 55
I. KlIAI NI$M .................................................................................................. 55
II. DlNHLU,ATOIIM ....................................................................................... 55
III.NUT NHAN .................................................................................................. 57
IV. VALVEDISNTV................................................................................... 57

V. RELAY ......................................................................................................... 62
VI. CONG TAC HANH TRINH ................................................................... 65
VII. RELAY THOI GIAN .............................................................................. 69
VIII. CONG TAC AP SUAT ··········································································· 72


4

CHUONG I: KHAI NIEM
. VE KHi NEN VA UNG DUNG
. CUA
KHiNEN
Gi6i thi~u:
Trong chuang nay se cho nguai h9c c6 nhung kiSn thuc, khai ni~m vS khi nen
va nhfrng ung dvng trong h~ th6ng tv d9ng h6a, CO' di~n tu.
Muc tieu:
~ Nim ro cac quy dinh trong h'.ic thvc hanh cung nhu cac n9i quy an toan lao
d9ng.
- BiSt duqc m9t s6 d~c diSm h~ th6ng truySn d9ng bing khi nen.
- Cong thuc tinh toan va CO' so cua h~ th6ng kin nen
- Nh~n d~ng duqc cac thiSt bi cong nghi~p.
I. S\f PHA.T TRI~N CiiA Ky THUiT KHi NEN
Nhu chung ta da bi@t, khong khi nen la m9t d~ng nang luqng cu ma con
nguai da SU dvng thay th@ cho cac Ive CO' h9c.
Tu hang ngan nam tru6c, khong khi da nen dSn muc c6 th@ chay duqc. N6
con la m9t trong b6n phAn tu CO' ban duqc thua nh~n boi nguai xua. Nguai ta SU
dvng chung m9t each c6 y thuc ho~c vo thuc.
M9t trong nhfrng bu6c d§.u tien la sv hiSu biSt cua chung ta vs vi~c ung dvng
ky thu~t khi nen, c6 nghfa la dung khong khi nen dSn muc c6 th@ chay duqc dS
cong tac. M9t nguai Hy l~p ten KTESIBIOS, each day han 2000 nam, da ch@

t~o ra may bin da dAu tien bing khi nen. M9t trong nhung cu6n sach dciu tien da
ghi l~i vi~c su dvng khong khi nen nhu m9t ngu6n nang luqng vao ngay dciu tien
cua cong nguyen. N6 da mo ta lc;ti cac b9 ph~n diSu khiSn bing khong khi n6ng.
Tu "Pneuma" la tu c6 Hy lc;tp c6 nghfa la gi6, la hai tho va trong TriSt h9c n6
c6 nghfa la linh h6n.
"Pneumatic" la m9t trong nhung each mieu ta tu "Pneuma". D6 la nganh
khoa h9c vS khi d9ng Ive h9c va cac hi~n tuqng lien quan da duqc due kSt.
sv hiSu biSt cua nhan loc;ti vs khoa hQC khi nen tu nhung th@ ky d§.u, song
phai cha dSn th@ ky nay m6i duqc chung ta nghien cuu c6 h~ th6ng. Tu khi d6
ky thu~t khi nen da thvc sv di vao cac nganh cong nghi~p.
DiSu dang quan tam la khong khi nen duqc ap dvng r9ng rai trong cac llnh
vvc quan tr9ng, vi dv nhu trong cong nghi~p khai thac qu~ng mo, duong sit, d~t,
cong nghi~p thvc phim, ...
M~c du ban dciu c6 nhiSu thiSu sot nhung sv b6 sung thuong xuyen nhung tri
thuc, kinh nghi~m thvc tS nen sv ap dvng ky thu~t khi nen duqc phat triSn ngay
cang mc;tnh han.
Ngay nay khong khi nen duqc dung r9ng rai trong cac nha may hi~n dc;ti,
duqc b6 tri thanh h~ th6ng ngu6n cung c~p nhu h~ th6ng di~n.
II. NHfrNG DaC TRUNG CiiA KHONG KHi NEN
C6 thS nguai t~ se ngc;tc nhien vs nhung tiSn b9 vuqt b~c trong li'nh V\fC khi
nen v6i m9t thai gian qua ngin.


5
DiSu nay c6 thS tv hiSu nhu m9t sv k:i~n ma ta k:hong thS khong nh?n biSt
r~ng khong m9t each nao don gian hon va hgp ly hon dS giai quySt nhfmg v§n
dS ca khi h6a va tv d9ng h6a.
Cac d~c trung ca ban cua khong khi nen la:
• v~ s6 hrgng: khong kW c6 sin a khiip nai nen c6 thS nen v6i s6 luqng VO
he;1n

• v~ vin chuy~n: khong khi nen c6 thS V?n chuySn trong cac duong 6ng, v6i
m9t k:hoang each nh~t dinh. Cac duong 6ng dftn vS thi khong dn thiSt vi khi
se duqc cho thoat ra ngoai moi truong sau khi da cong tac.
• v~ hru trfr: may nen khi khong nh~t thiSt phai hoe;1t d9ng lien t1_lC. Khi nen c6
thS duqc luu trfr trong cac binh chua, duqc liip n6i trong cac h~ th6ng 6ng
d~n dS cung cfip cho su d1.1ng khi cAn thiSt.
• V~ nhi~t dq: khong khi nen it thay d6i theo nhi~t d9.
• V~ ch6ng chay n6: khong m9t nguy ca nao gay chay bai khi nen, nen khong
t6n chi phi phong chay. Hoe;1t d9ng v6i ap sufit khoang 6 bar nen phong nb
khong qua phuc te;1p.
• V~ tinh s~ch se: khi nen thi trong se;1ch, ngay ca trong truong hgp la dong
chay trong cac duong 6ng hay la trong cac thiSt bi, khong m9t nguy ca gay
bAn nao duqc quan tam dSn. Tinh chfit nay rfit cAn thiSt trong cac nganh cong
nghi~p chuyen bi~t nhu cong nghi~p thvc phAm, vai sqi, lam san va thu9c da.
• v~ ciu t~o cac trang thi~t bj: don gian nen re tiSn
• V~ vin t6c: khong khi nen la m9t dong chay c6 luu t6c 16n, cho phep de;1t
duqc t6c d9 cao (v?n t6c lam vi~c cac xy lanh thuong tu 1-2m/s, ca bi?t c6
thS de;1t dSn 5 mis).
• v~ tinh di~u chinh: V?n t6c va Ive cua nhfmg thiSt bi cong tac b~ng khi nen
duqc diSu chinh m9t each vo cfip.
• v~ S\f qua tai: cac cong C\l va cac thiSt bi khi nen dam nh?n tai tr9ng cho dSn
khi chung dung hoan toan, cho nen se k:hong xay ra qua tai.
I)S phan dinh m9t each c~n ke cac li'nh V\fC ap d1.1ng ky thu?t khi nen, cAn
phai biSt dSn cac tinh chfit khong thS khong chu tr9ng dSn nhu:
• Cach xii: ly: k:hong khi nen phai duqc chuAn bi sao cho khong chua b1.1i
bAn, te;1p ch~t hay nu6c, vi chung se gay mon cho cac phAn tu khi nen.
• Tinh <;htu nen: khong khi c6 thS nen duqc cho phep.thay d6i va diSu chinh
V?il toe cua piston.
• D9 !an ll;CC tac dlf,ng: khong khi duqc nen se khong kinh tS nSu chua de;1t
m9t cong sufit nhfit djnh. Ap sufit lam vi~c thuong duqc chfip nh?n 7 bars.

D9 16n Ive gi6i h~n tu 20.000 - 30.000 N (2.000 - 3.000 kp), con ph1.1
thu9c vao V?n t6c va hanh trinh.
• SI:C thoat : khi khi nen xa se te;10 ra am thanh 6n, nhung nha c6 cac b9 ph?n
giam thanh giin a tung duong thoat do d6 vfin dS nay cfing da duqc giai
quy@t.
• Gia thanh: khong khi nen la ngu6n nang luqng d6i dao, don gian va siln
c6 nen gfa thanh cua h? th6ng SU d1_lllg se re.


6

III.

oic TiNH CUA KHi NEN

Khong khi chung quanh ta c6 ap su:it thay d6i, n6 ph\l thu9c vao:
• f>Q cao so v6i ID\fC nu6c biSn
• Vi tri dia ly
• Khi tuQTig
Chung ta c6 thS phan lo~i cac lo~i ap su:it sau:
A.p suit khi trCYi: la ap su:lt khong khi chung quanh ta. Ap su:lt nay b~ng
1013mbar 6 m\fc nu6c biSn, o0 va 6 vituySn 45°
A.p suit chan khong: NSu khi quySn biSn m:it chung quanh qua d§.t, ap su:it
khong con nua, ta c6 chan khong tuy~t d6i. Ap su:it duqc biSu di@n so v6i chan
khong tuy~t d6i g9i la Ap su:it tuy~t d6i.
A.p suit du: la ap suit d9c duqc so v6i ap suit khi quySn
Khong khi dung trong cong nghi~p luc d~u la khong khi 6 ap suit khi trai,
duqc tang len m9t ap suit cao g9i la Ap su:11 tuang d6i hay con g9i la Ap su:it
du (ap suit do)

Ansudt

An sudt khi

An sudtchan

A.p sudt chan kh6ng

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IV. CA.CDAILUONG
. VAT
. LY
BS m~t dia c~u duqc bao quanh b6i m9t 16p khong khi. Day la m9t h6n hqp cac
khi ck thiSt cho S\f s6ng, c6 ty 1~ tuang ung nhu sau:
• Nita chi@m 78% thS tich
• Oxy chSm 21 % thS tich
• Con l~i la m9t s6 khi khac nhu: carbonic, argon, hydro, neon, heli, cryton,
vaxenon
f)S hiSu ro them cac dinh lu~t vs d9ng l\fC h9c va tr~ng thai cua khong khi,
nguai ta da li?t ke ra sau day cac thong s6 v@ v~t ly va cung v6i cac h~ th6ng do
luang.
f)S thu~n lqi trong vi~c nghien Clfll va ung d\lllg, nguai ta thuang dung
hai h~ th6ng do: h~ th6ng do "Ky thu~t" va h~ th6ng do "SI".
Cac thong sB CO' ban


7

Thong s8
Chieu dai
Kh6i luqng
Thai gian
Nhi~t d()
Cuang d() dong
di~n
Cuang d() anh
sang
,
- xuat
Cac thong so dan

Ky hi~u
1
m
t
T
I

H~ ky thu~t
Met (m)
Kp.s 2/m
Giay (s)

uc

Ampere (A)

Cd

Cadela

Ky hi~u

Thong s8
Lvc

F

Di~n tfch
ThS tfch
Luuluqng
Ap suit

A
V
Q
p

H~SI
Met (m)
Kg
Giay (s)
UK
A

He SI
IN= 1

kg.m/s2
m2
m3
m3/s
Pa
1 Pa= 1 N/m2
Bar
1 Bar= 105 Pa
,
'
lucmg ky thuq,t va quoc te ta c6 cong thuc
H~ kv thu~t
Kp=kg.f=
9,8N
m2
m3
m 3/s
at
( ky thu~t)
kp/cm2

Kit h(JJJ giua hf thong tlo
Newton
F=m.a
trong d6: m - khf>t luqng
a - gia toe
g- gia t6c tn,mg truang ( g = 9,81 m/s2)
Giua cac cong thuc tren t6n tc;d m6i quan hf sau:
Kh8i lu(fng 1 (kg)= 1 kp.s 2/ 9,81.m
L{l'c

l (kp) = 9,81 (N)
DS don gian cho tinh toan ta liy 1 (kp) = 10 (N)
Nhift iii)
0 diSm 0:
o0c = 273 K (Kelvin)
d nhi~t d9 khac: 1°c = 1 K (Kelvin)
Ap suat
* Atmosphere, [at]:
1 at= 1 kp/cm2 = 0,981 bar
* Pascal, Pa ; bar: 1 Pa= 1N/m2 = 10-5 bar va 1 bar= 10-5 N/m2 = 105 Pa= 1 02
at
* Atmosphere v~t ly, atm: 1 atm = 1,033 at= 1,013 bar
* Milimet c9t nu6c, mm c()t nu6c: 1000 mm c9t nu6c =lat= 0,981 bar
*Milimet thuy ngan, mmHg: 1 mmHg = 1 Torr,
lat = 736 Torr, 1 bar = 750
Torr
JJjnh lu{l,t Boyle - Mariotte


8

d nhi~t d9 c6 dµih, tich s6 thS tich va ap su&t tuy~t d6i cua m9t khi ly
tuong la h~ng s6.
Ptuy~t ctbi

x V = constant

8bar
4bar

2bar

lbar

~H---11- - - ~

Bjnh lu~t Gay-Lussac
6 mkhi ly tuang la h&ng si
- - = constant
Ghi chu: Nhi~t d9 tJ~ctt6i luon luon dugc tinh b~g d9 Kelvin
o° K (Kelvin)= -237°C (Celcius)

A
Pa

---

%

Ta

(,_)

P1

1/

Va

n

T1

0.:1:z:

V1

/---.

(

\ ...

◄-)--···

'-__/ I\ (1 ()Jj_
,-~ \

Bep di~n

Bjnh lu~t Charles
d m9t thS tich c6 dinh, ty s6 giua ap su&t tuy~t d6i va nhi~t d9 tuy~t d6i
cua m9p; khi ly tuong la htmg s6.
tuy~t d6; = constant
Dinh 1J~t~OO.g hgp ca 3 biSn (ap su&t, thS tich, nhi~t d9 dugc cho b&i
Phuong trinh tqmg thai nhi?t t6ng quat cua khi nen:
Pabs . V = m . R. T
Trong d6 : p abs [bar]
: ap su§.t tuy?t d6i

9

V [cm3]
m [kg]
khi tinh bkg kg/m3
R [J/kg.K]
T [K]
Ap su~t Pa
bar

: thS tich khi nen
= V . r : kh6i luQTig, r la kh6i luQTig rieng cu.a khong

: h~ng s6 khi
. nh""t
1.
1~ d"
9 tinh b~ang K evm
at
mbar
mmWs Torr
psi
atm
Kp/cm2 Kp/cm2 MmH
7,50.1( 1,45.10- 0,987.1
1,000.1 1,000.U 1,02.10- 0,102

1 Pa

1
o-s
1 N/m2
1,000.1( 1
1 bar
5

2

5

1,000.U 1,02

4

o-s

1,02.10~ 0,75.1( 1,45.10 0,987

3

3

1 mbar 1,000.1( 1,000.1 1
2

3

o-3 .

1,02.10- 1,02.10 0,75

1,45.10- 0,987.1

3

2

o-3

2

0,981.1( 0,981 9,81.10 1
1 at
1,000.U 7,36.lC 1,42.10- 0,987
5
4
2
2
1
kp/cm2
lmmW 9,81
0,981.1 9,81.10- 1,000.1 1
7,36.lC 1,42.10- 9,68.10-

s

o-4

2

2

o-4

3

5

1 kp/m2
1,36.10- 1,36.10 1
lmmH 1,33.102 1,33.10 1 33
1,934.1 1,32.10'
3
3
3
o-2
g
1 Torr
6,895.1( 6,895.1 6,895.1 7,033.1 7,033.11 5,171.] 1
1 psi
6,805.1
3
2
o-2
o-2
o-2
0
0
2

1,013.1( 1,013 1,013.U 1,033
1 atm
1,033.11 7,6.10 1,469.1 1
3

5

4

o-2

p
dyn
kp
Mp
N
5
4
1,02.101
10
0,102
102
6
9
1,02.101,02.101,02.10-3
10-5
1
10-3
9,81
9,81.10 5

1
103
9,81.10 3
9,81.10 8
103
106
1
10-3
10-6
9,81.10-3
981
1
Dan vi cu.a cong la Joule (J). 1 Joule (J) la cong sinh ra du&i tac d(mg cu.a
lvc 1 N dS v~tdich chuySn quangrciuimg lm.
j
1
10-7
9,81
3,60.10 6
4187

erg
107
1
9,81.10 7
3,60.10 13
4,19.10 10

kpm

~
.m 2k:~
l<.I -1--; Kwh

0,102
1,02.10-8
1
3,67.10 5
427

2, 78.1 o-'
2,78.10-4
2,72.10-o
1
1,16.10-3

Kcal
2,39.10-4
2,39.10- 11
2,34.10-3
8,60
1

eV
6,24.10 18
6,24.10 11
6,12.10 19
25
2,25.10
22

2,61.10


10
1,63.10-20 \ 4,45.10-26 \ 3,83.10-23 \ 1
I
Don vi cua cong suit la Watt (W). 1 Watt (W) la cong suit trong thai gian 1
s, sinh ranang Iugng 1 J
1 W - 1 Nm/s
Kpm/s
PS
Kcal/s
Kcal/h
kw
w
4
3
3
101,36.102,39.100,102
0,86
1
3
102
1,36
1
0,239
860
10
4
3

2
1,33.109,81.1023,45.101
8,43
9,81
75
1
735,5
0,7355
0,1757
622
5,69
4187
4,19
427
1
3600
3
3
4
1,58.101,16.102,78.100,119
1,16
1
,
,
.,
V. KHA NANG UNG DVNG CUA KIii NEN
1. Trong Iinh V\fC di~u khi~n
H~·th6ng diSu khiSn bfulg khi nen duqc SU d1=1ng (J nhfrng IInh vvc c6 kha
nang nguy hiSm nhiSu nhit nhu: chay, n6 ... , vi dv nhu cac thiSt bi phun son, cac
10<;1,i d6 ga, k~p chi tiSt, plastic, ho~c duqc sir dvng trong nhfrng IInh vvc san xuit

cac thiSt bi di~n tu. Ngoai rah~ th6ng diSu khiSn bfulg khi nen duqc sir dvng
trong cac day chuySn rua tl_! d9ng, trong cac thiSt bi v~n chuySn va kiSm tra lo
hai, thiSt bi m? di~n, dong g6i, bao bi va trong cong nghi~p h6a chit.
2. H~ th6ng truy~n dqng
• Cac d\lllg C\l, thiSt bi may va d~p: may khai thac da, Imai thac than, xay
dl_!llg hAm mo, duang hAm ...
• TruySn d9ng quay: cac d9ng ca quay v6i cong suit Ian, m~c du gia thanh
dit gip 10 dSn 15 Ik so v6i d9ng ca di~n c6 cung cong suit, nhung thS
tich va tr9ng lugng nho hon 30%. Nhfrng dvng Cl.) v~ vit tu M4 dSn M30,
may khoan c6 cong suit khoang 3,5kW, may mai c6 cong su~t khoang
2,5kW
• TruySn d9ng thing: duqc sir dvng trong cac d6 ga k~p ch~t, cac thiSt bi
dong g6i, may gia cong g6, trong cac thiSt bi lam l?nh, cung nhu trong cac
h~ th6ng phanh ham cua o to.
• Trong cac h~ th6ng do va kiSm tra, trong cac h~ th6ng v~ chuySn xi
mang.
VI. UU NHUOC BIEM CUA HE THONG TRUYEN BONG BANG KHi
NEN
.
.
.

I 1,6.10-19

I l,6.10- 12

¥

\

?

1. Uu di~m
Do kha nang chju nen (dan h6i) Ian cua khong khi, do v~y kha nang tich
chua ap suit nen m9t each thu~n lqi. Nhu v~y c6 kha nang ung d1;mg dS thanh
l~p m9t tr?m tich chua khi nen.
• Co kha nang truySn tai nang lugng xa, bai vi d9 nh6t d9ng h9c cua khi
nen nho va t6n thit ap suit tren duang d~n it.
• Duang d~ khi ra (khi thai) khong ck thiSt
• Chi phi thip dS thiSt l~p m9t h~ th6ng truySn d9ng bfulg khi nen
• H~ th6ng phong ngira qua tai ap suit gi6i h?n duqc bao dam.


11

2. Nhrrqc di~m
• Lvc truySn tai tr9ng nho
• Khi tai tr9ng trong h~ th6ng thay d6i, thi v~n t6c truySn cfing thay d6i, vi
kha nang dan hf>i cua khi nen 16n, do d6 khong th@ thvc hi~n duqc nhung
chuy@n d(mg thilng ho~c quay dSu.
• Khi thoat ra gay ra tiSng f>n
Do d6 hi~n nay, trong li'nh vvc diSu khi@n nguai ta thuang kSt hqp h~ th6ng
diSu khi@n bfulg khi nen v6i CO' khi, ho~c khi nen v6i di~n, di~n tu. Do v~y dt
kh6 xac dpih m9t each chinh xac uu khuySt di@m cua tung h~ th6ng diSu khi@n.
vn. cAc Lo4-1 MAY KHi NEN vA THIET BJ xuLv KHi NEN
1. May nen khi:
a. May nen ki@u Piston (Hinh 2.2):
- M()t cfip: ap su§.t xfip xi 600kPa= 6 bar
- Hai d.p: ap su§.t x§.p xi 1500kPa- 15bar. C6 thS thiSt kS dSn 4 cfip, P 250bar
Luu luqng xfip xi 1Om3/min. Lam vi~c theo nguyen ly thay a6i thi tich

piston compressor

Refrigeration

H1nh 2.2

b. May nen kiSu canh g~t (Hinh 2.3):
- M(>t cfip: ap sufit xip xi 400kPa 4bar
- Hai cfip: ap su§.t x§.p xi 800kPa = 8bar
Lam vi~c theo nguyen ly thay a6i thi tich
Luu luqng thS tich Qv ty 1~ thu~n v6i:
·Buang kinh stator, s6 canh va d9 r()ng canh g~t,
d9 l~ch tam va t6c d9 quay rotor.
c. May nen khi ki@u trvc vit (Hinh 2.4):
Lam vi~c theo nguyen ly thay a6i thi tich
Ap sufit 16n, xfip xi 1Obar
Luu luqng ty 1~ thu~n v6i t6c d9 quay,
chiSu dai tfl_lC vit.
d. May nen khi ki@u ly tam (Hinh 2.5):
Lam vi~c theo nguyen ly a<)ng nang

Sliding vane compressor

:~
'

H1nh 2.5

tJ

!SSOr


12
Ap su§.t kha 16n, x§.p xi 1OOOkPa 1Obar
Luu lugng ty l? v6i t6c d9 quay, s6 canh va di?n
tichcanh.
e. May nen khi kiSu hu6ng tf\lC (Hinh 2.6):
Lam vi?c theo nguyen ly dong nang
Ap su§.t x§.p xi 600kPa~6bar
Luu lm;rpg cfing tf l? v6i t6c d9 quay, du~h 2.6
kinh buong hut, so canh va di?n tich canh
2. ThiJt bj xii' ly khi nen
Cac giai do~n XU ly khi nen:
- LQC tho: lam mat SO' b9 dS tach chĐ.t bfui, bài; tiSp 11:-- . -- ---~- --c,---o
tach hoi nu6c.
Axial compressor
- S§.y kho: Qua trinh v~t ly hay qua trinh hoa h9c.
- LQC tinh: Dung b9 l9c va C\}m bao duong (DiSu hoa, ph\lC V\l )
1. B9 l9c va s§.y kho khi nen (Hinh 2.7)

t

- ....

dS

1111
c=l

Khf nen ter may nen khf
Khf nen n6ng S.;lCh s~ kh6
c::J Chat lam l,;lnh long
~ Chat lam l.;lnh d.;lng khf

-I

t

0() ~m. d~u l§n, b1,,1i

1-Hnh ? 7

Nguyen ly ho~t d9ng cua phuang phap s§.y kho bfug ch§.t lam l~nh: khi
nen tu may nen khi se qua b9 ph~n trao d6i nhi?t khi-khi (1 ). T~i day dong khi
nen vao dang n6ng se dugc lam l~nh nha trao d6i nhi?t v6i dong khi di ra da
dugc s§.y kho va lam l~nh. Nhu v~y, t~i khau nay : khi nen vao dugc lam mat,
khi nen di ra dugc suoi §.m.
Sau khi dugc lam l~nh SO' b9, dong khi nen tiSp t\}C di vao b9 trao d6i
nhi~t khi-ch§.t lam l~nh(2). T~i day, dong khi nen dugc lam l~nh dSn nhi?t d9
h6a suang ( khoang +2°C), cac gi9t suang ( mang theo dftu l~n va b\li) se ngung
l~i trong thiSt bi (3). Van xa (4) dung dS xa nu6c, dftu l~n va b\li. Cac thiSt bi:
(5, 6, 7, 8) dung dS t~o ch§.t lam l~nh v6i kha nang tv d9ng diSu chinh luu lugng,
nhi~t d9 cua ch§.t lam l~nh.
(1) B9 trao d6i nhi~t Khi-Khi
(2) B9 trao d6i nhi?t Khi-Ch§.t lam l~nh
(3) B9 ngung t\}, kSt tua
(4) Van xa
(5) May nen diSu ch@ ch§.t lam l~nh
(6) Binh ngung t\l

(7) B9 diSu chinh luu lugng ch§.t lam l~nh


13
(8) B9 diSu chinh nhi~t d9 ch~t lam l<;tnh
2. B9 diSu hoa phvc vv ( AIR SERVICE EQUIPMENTS) (Hinh 2.8):

~-----------'

Ky hi~u
H1nh 2.8

89 dieu hoa ph1,1c v1,1
Gf>m:
- B9 l9c hai nu6c
- Van diSu chinh ap su~t
- Df>ng hf> chi thi

+ B9 l9c khi nen (Compressed air Filter) (Hinh 2.9)

89 l9c

Nguyen ly l9c: Khi nen t<;10 chuy@n d9ng
Hinh 2. g
xoay va qua dugc ph~n tu l9c c6 kich thu6c
tu 5 µm dSn 70 µm tuy theo yeu c~u.
Hai nu6c bi ph~ tu l9c ngan l<;ti, rai xu6ng
c6c l9c va dugc xa ra ngoai.
+ Van diSu chinh ap su~t c6 cua xa tran(Pressure regulating valve with relief
port) (Hinh 2.10)

·Chuc nang: duy tri ap su~t lam vi~c kh6ng d6i trong ph<;tm vi r9ng, kh6ng phv
thu9c vao sv dao d9ng ap sufit a m<;1ng cung cfip khi nen va phia tieu thv khi nen.


14
DiSu ki~n cfin la ap su~t 16i vao luon phai cao hon ap su~t lam vi~c cfin cho CO'
ciu chip hanh.
Nguyen ly lam vi~c:
Khi ap suit P 2 , vi d\l tang len do tai tr9ng cua xilanh, khi nen a day c6 thS ti;r
thoat ra ngoai qua m<)t khe h~p.

Hinh 2.10

Pl.

P2

p·1

P2

B9 dieu chinh ap suat
3. Cac phln tfr ch,p hanh (working elements)
T6ng quat:
TruySn d<)ng khi nen la thvc hi~n biSn d6i nang luQTig khi nen thanh cac d:;mg
d<)ng nang khac:
- ChuySn d9ng thing:
+ Xilanh tac d\l,llg don ( Single acting Cylinder)
Endposition
Rea,

+ Xilanh tac d\lng kep ( Double acting cylinders)
front
+ Xilanh quay (Rotary Cylinders)
- ChuySn d<)ng quay:
+ D<)ng ca khi nen (Air Motors)
- Giac hut
a. Xilanh tac d1.mg don: (Hinh 2.11)
* Khi nen chi duqc su d\lng dS sinh
Sfngle-acrir1g cylinder
cong a m<)t phia cua Piston. Piston
8ieu khien tn,.rc ti§p xilanh tac d1,mg dan
b~ng nut .!in 3/2
lui vs bing Ive b~t l~i cua lo XO hay cua Ive
tu ben ngoai.
Piston

Hinh 2.11a
Ky hieu

b. Xilanh tac d\lng kep: (Hinh 2.12)
* Khi nen duqc SU d\lng ca hai phia cua Piston. Xilanh c6 thS sinh cong
theo ca hai phia cua Piston.


15
* Do di~n tich cua hai m~t Piston khac nhau nen Ive tac d9ng tren cftn
Piston cung khac nhau.
* DiSu khiSn bing van 4/2; 5/2 ho~c 5/3

Hinh 2.12

Kv hieu

c. Xilanh tac dgng kep c6 d~m giam ch&n (Hinh
2.13)

Dou ble-atting .:yHnde r

Advance

...

J

I+

+

0ieu khien tn,1c tiep xilanh
tac dung kep b~ng nut an 5/2

Hinh 2.13

d. Xilanh quay
DiSu khiSn bing van 4/2; 5/2 hay 5/3

Ky hi~u
Xi lanh quay

Hinh 2.16

Cftn Piston c6 thanh rang truySn d9ng toi banh rang quay, g6c quay


16
0- 360°, momen khoang 0,5Nm dSn 20Nm
duong kinh cua Piston.
e. D(mg

CO'

a ap su§.t vc%n hanh 6bar, tuy thu9c
~

fr

y-

khi nen:

Ky hi~u

* KiSu canh g?t (Hinh 2.14)

Hinh 2.14

Dong CO' c6 thS quay tron lien u.ic
C6 thS dao chi@u quay,

09ng cd khf nen kieu canh gr,1t

diSu khiSn bing van 4/2; 5/2 hay 5/3

ff

* KiSu truySn d9ng xoay (Hinh 2.16):

Ky hi~u

DiSu khiSn bing van 4/2; 5/2 hay 5/3.

Hinh 2.15

Goe xoay 0-2 7 0°

•

I

I

I

T

I

.N

Momen: khoang 0,5Nm dSn 20Nm a ap su§.t

vc%n hanh 6bar va ph\l thu9c vao kich

2

thu6c cua canh g?t.
f.

Giac hut: (Hinh 2.17)

M9t vong lorn bing cao su co thS treo m9t
v~t bing sue hut khi nen.
Khi co khi nen th6i tu 2 sang 3, mi~ng hut 1 se
t?0 chan khong cho giac hut.

Hinh 2.17

'·'

',

Giac hilt
(Sucker)

Van hilt chan khong
(Vacuum suction nozzle)

Mr,1ch khf nen dung giac hut


17

CHUONG II: THIET KE, LAP D~T VA V4N HANH H$
THONG KHi NEN
Gioi thi~u: Trong chuong nay se cho nguai h9c c6 nhfmg kiSn thuc, ky
nang thiSt kS, Hlp d~t va v~n hanh voi khf nen va nhung ung d\lllg trong h~ th6ng
tv d9ng h6a, CO' di~n tu t~i nhung nha may khac nhau.
Ml}C tieu: Trang bi cho h9c vien nhfmg kiSn thuc chuyen mon va ky nang
nghS nhu sau:
Ki~n thfrc chuyen mon: thiSt kS, lip d~t, v~n hanh h~ th6ng khf nen theo
yeu c~u, nh~n biSt nhfmg lo~i van, co c§u khf nen ....
Ky nang ngh~: KiSm tra, thay th@, sua chfra, Nang c§,p - cai tiSn. Phan
tfch h~ th6ng di~n va thiSt bi trong tu di~n diSu khiSn.
Thai dq lao dqng: T~p trung, cham chi.
Cac ky nang cfin thi~t khac: Nh~y ben, sang t~o, nang d()ng.
I. cAc LO~I VAN KHi NEN
1. Ky hi~u chung ciia van di~u khi~n dao chi~u (Directional control
valve)
Quy uoc biSu diSn cac c6ng vao/ra, cac vi trf chuySn tr~ng thai:

I

II

Number of ports
Numberofswitchingpositions

2/2-way valve, normally open position

3/2-way valve, normally closed position

3/2-way valve, normally open position
4/2-way valve
flow from 1 ➔ 2 and from 4 ➔ 3
5/2-way valve
flow from 1 ➔ 2 and from 4 ➔ 5
5/3-way valve, mid-position closed

Trong d6, ky hi~u cac c6ng lam vi~c:
Part designations

Port deslrrnation in accordance with DIN ISO 5599·3 "Fluld TechnologyPneumattts, 5-Way Valves•i
Whrking ports

• 1

Supptyport

•· 2,4

Working ports.

• 3,5

Exhaust ports

- Quy uoc biSu diSn cac d~ng tfn hi~u diSu khiSn van (Hinh 2.18):


18
Types of Actuation

Manual actuati,o n

Mec::hanl:cal ac.tuatlon
Rolliu attual£>d
"' Ro lier .tt luaf.i:d only in
o ne ,d Ir•ettio n

-Spring center£
Pneumatic. ;actuation

~
._.-L

Dir,ect pneun.wth: actuation

Ind iret t pnceu n:i.:i.Li.i:: ,a.ct uath'.1 rt.,
pik1led

~

r-r-r

Solenoid .ac.tuatio.n

~

cz::[
Comibined actuation

J=o

'"" Doubl,e solenoid \<'.!tl/',e.,
piloted, with manual owrrh:le

Hinh 2.18
Quy u'oc ky hi~u cac cong dieu khien:
Pilot ports

• 10

Signal applied blocks flow from 1 to 2

•

S15nalapplie,d o,pel:'IS flovtJ front 1 to 2
Stgnal appli.ed opens fto.w from 1 to i1,
Au.x.ilfarypilot.air

'12

• 14
• 81,91

Vi dlJ ve ky hi~u day du cua m{jt so van (Hlnh 2.19)
12

rrrn.,VVv

~ .

91

· mitfl

12

:}~
1

H1nh 2.19


19
Vi dv vS ho~t d<)ng cua van va xilanh

Hinh 2.20

2. Cac van dao chi~u di~u khi~n bing khi nen
a. Van 2/2, ky hi~u va kiSu dang
(hinh 2.21)
Van 2/2 c6 hai c6ng vao/ra, hai tqmg
thai.
Va phfui 16n SU dlJllg van 2/2 lam
kh6a ON/OFF dong, ma ngu6n khi nen. Hinh 2 _
21
Van 2/2 c6 thS diSu khiSn bfulg tay,
bing
tiSp xuc CO' khi hay bing khi nen.
b. Van3/2

Van 3/2 c6 3 c6ng lam vi~c ( vao, ra va c6ng xa)
Cac van 3/2 dugc chS t~o r~t da d~ng va ung dlJllg cfing r~t phong phu. D~ng tac
d<)ng c6 thS bing tay, bing tiSp xuc ca khi (trgc ti@p ho~c qua van phv trg), bing
khi nen hay bing di~n & m<)t phia ho~c ca hai phia. Cac van diSu khiSn ca hai
phia c6 d~c tinh nhu m9t phfui tu Flip-Flop. Hinh 2.22 mo ta m9t s6 ung dvng
van 3/2.

Cong t ~c hanh trlnh khi nen 3/2
Cong ~c khi nen 3/2

Van dao chieu 3/2 difu khie'n bang di~n tu'
Van dao chieu 3/2 difu khie'n bang khi nen

Hinh 2.22
Hinh 2.23 trinh bay ky hi~u, nguyen ly c~u t~o - mo ta nguyen ly lam vi~c cua
m<)t van dao chiSu 3/2:


20
.,,,·,

;,-:;,~"

Khi c6 tfn hi~u dieu
khien

Khi chu'a c6 t fn hi~u

dieu khien

Hinh 2.23

D~c diSm:
* Tin hi~u diSu khiSn bing khi nen chi tu m9t phia, phia con h;ti tac
d(mg cua lo XO phan khang.
* Tr~ng thai yen l~ng do tac d9ng cua lo XO - thuong dong.
* Ten g9i: Van aao chi&u 3/2 thucrng a6ng ai&u khiin m(>t phia
b&ng khi nen.
c. Van 4/2
Van 4/2 co 4 c6ng lam viec ( m9t vao, hai ra va chung m9t c6ng xa), hai
tr~ng thai. VS nguyen ly c~u t~o, van 4/2 duqc ghep b&i hai van 3/2: m9t thuong
dong, m9t thuong ma
Van 4/2 cilng co thS diSu khiSn bing ca khi, bfug khi nen hay di~n m9t
phia ho~c ca hai phia. Cac van diSu khiSn bing khi nen hay di~n ca hai phia co
d~c diSm nhu m9t ph~n tu Flip- Flop.
Hinh 2.24 biSu di@n ky hi~u, nguyen ly c~u t~o va ho9-t d9ng cua m9t s6
ung dvng cua van 4/2
4/2-way

4

2

1

1
M

u..

...

a

1
U.J..:',

4

1/-r!_

Van 4/2 dieu khien bang khf nen 2 phfa

Van 4/2 tac d9ng bang cd khf

Hinh 2.24

2


21

Van 4/3 c6 4 c6ng lam viec ( m9t vao, hai ra va chung m9t c6ng xa), ba
tqmg thai. Tqmg thai thu ba duqc them vao la tr~ng thai trung gian, thuong n~m
gifra hai tr~ng thai v6n c6.
Hinh 2.25 mo ta m9t cong ti\c d~g tay g~t dung van dao chi@u 4/3. Day la d~ng
van truqt phfulg, co thS dung cho di@u khiSn Xilanh tac d1,mg kep. Khi do cfin
Piston co thS dung a b~t ky vi tri nao trong khoang ho~t d9ng cua no, tuy nhien
ft co kha nang dung chfnh xac theo y mu6n. D9 chfnh xac diSm dung con phv
thu9c vao tai tr9ng d~t vao cfin Piston.

3

Ky hi~u

3

4

2

Hinh 2.25

3

4

2


22
e. Van 5/2
Van 5/2 c6 5 c6ng lam vi~c( m()t vao, hai ra va hai cira xa rieng cho m6i
tn;mg thai, c6 hai tqmg thai.
Van 5/2 cfing c6 th@ di@u khi@n bing co khi, bing khi nen hay di~n m()t phia
ho~c ca hai phia. Cac van di@u khi@n bing khi nen hay di~n ca hai phia c6 d~c
diSm nhu m()t ph§.n tir Flip- Flop. Con g9i la van dao chiSu 5/2 - xung (Van c6
nh6). NSu cac tin hi~u khi nen 12, 14 cung duqc sir dl_lng, tin hi~u dSn tru6c se
c6 uu thS diSu khi@n.
- Dung lam van dao chiSu diSu khi@n xilanh tac dl_lng kep
- Dung lam cong t~c ap su~t

C6 kha nang nh6 tr~g thai, tin hi~u tac d()ng diSu khi@n d~ng xung
( tin hi~u ng~n).
Hinh 2.26 bi@u diSn ky hi~u, nguyen ly c~u t~o va ho~t d()ng cua m()t s6 ung
dl_lng cua van 5/2

14

5

4

1

2

3

12

Van 5/2 - xung (Flip-Flop) nho tu tfn hi~u dieu khien 12

14

5

4

1

2

3

12

Van 5/2 - xung (Flip-Flop) nho tu' tfn hi~u dieu khien 14

Hinh 2.26

Vi d\l vS ung dl_lng van dao chi@u 5/2 - xung (Hinh 2.27).
~

Hinh 2.27


23

f. Van 5/3
Khi co tin hi~u khi nen d~t vao c6ng 12(14), ngu6n khi nen se c&p qua duong di
1-2(1-4). Khi m&t tin hi~u diSu khiSn, nong van luon dvac lui vS vi tri gifra (vi
tri "khong") duoi tac d1_1ng cua lo XO.
Co mc)t s6 giai phap ky thu~t cho vi tri trung gian nhim dap ung yeu c~u cong
ngh~. Tren hinh 2.28 biSu diSn hai trong s6 cac giai phap d6.

14 5 4 1 2
3; 12
Van 5/3 - vj trf khong: tat ca cac cong lam vi~c deu kfn

14 5 4 1 2
3 12

Van 5/3 - vj trf khong: Hai cu'a ra deu du'qc noi v6'i cu'a xa

Hinh 2.28

u.

cAc L04-I VAN LOGIC

1. Van logic AND ( Dual Pressure Valve -AND Function) ( Hinh 2.29)

* Tin hi~u khi nen dugc dua vao cua 1 va 1(3) dS t~o tin hi~u ra 2
* Khi khong co cac tin hi~u vao ho~c chi co mc)t tin hi~u thi khong co tin hi~u
ra.
* Khi hai tin hi~u co cung ap su&t dugc dua toi a hai thai diSm khac nhau, tin
hi~u ra la tin hi~u vao dSn sau.
* Khi hai tin hi~u co ap su&t khac nhau dugc dua toi a cung thai diSm, tin hi~u
ra la tin hi~u vao co ap su&t nho han.

~

2
1

--lB-

11))

Ky hi~u tren so do
2

z 11 s21

1(3)

1

Tin hi~u vao 1(3) c6 trU'&c

Hinh 2.29
1

J.{3)

Tfn hi$u vao 1(3) c6 ap

suat nho hon

Vf d1,1 u'ng d1,1ng van AND